A: Heartworm disease is a serious and potentially fatal disease in dogs, and West Nile Virus can afflict horses with a serious illness that has a 40 percent mortality rate. Thankfully, Fort Dodge Animal Health offers new protection for both diseases: ProHeart® 6, the first six-month heartworm preventative in dogs; and a new West Nile vaccine, which recently received conditional approval by the USDA to prevent West Nile Virus infection in horses. Both products are now available through veterinarians.